The carbapenem antibiotic designated herein as Compound I: ##STR2##
is disclosed in U.S. Pat. No. 5,756,725 (WO 97/40048) and has been shown to be a highly effective, broad spectrum antibiotic. However, formulation of this compound into a form suitable for the market place has been hampered by the unavailability of a stable crystalline form.
Prior to this invention, purification of Compound I was performed by column chromatography and the thermally and hydrolytically unstable amorphous chloride or triflate salt forms and their formulations had to be stored at low temperatures. Now with the present invention there are provided non-hygroscopic, thermally stable, crystalline salts readilly obtainable by a crystallization process which serves to purify the product as well, thus, avoiding the use of chromatographic techniques.